Slitting device



April 10, 1962 J. o. T|| Y 3,028,670

SLITTING DEVICE Filed April 15, 1960 uw 5PZ. 5

INV EN TOR.

lames 0 Til@ United States Patent 3,028,670 SLITTNG DEVICE James O.Tilly, 4128 S. 32nd West Ave., Tulsa, Okla. Filed Apr. 15, 1960, Ser.No. 22,622 Claims. (Cl. 30--294) This invention relates to slittingdevices and to those devices particularly useful as letter openers orthe like and having provision for replacing the cutting blade.

in brief the invention comprises a body portionv of generally ilatplate-like construction, preferably formed of molded plastic materialand thus readily adaptable for the imprinting thereon of advertisingmaterial or the like. The body is provided with a slot extending closeto one edge and parallel thereto, and in the base of which a removablecutting blade is provided. The blade has a generally hook-shaped cuttingedge whereby to prevent jamming of paper or other cut material at anedge of the slot and the blade is further permanently secured to a bladeholder removable from the body. To replace the cutting blade it is onlynecessary to release and remove the blade holder and to replace the samewith a new assembly including a sharp cutting blade. The blade holder isprovided with integral resilient means serving to lock the same on thebody and the body is provided with an opening through which aninstrument may be inserted to displace the resilient locking means andthus release the blade holder for removal.y

lt is therefore an object of this invention -to provide an improvedslitting device suitable for use as a letter or carton opener and alsouseful for other purposes.

Another object of the invention is to provide a slitting device of thetype set forth which is inexpensive to produce yet highly efcient andreliable and endurable.

Still another object of the invention is to provide-a slitting device offiat plate-like configuration whereby it may serve also for novelty oradvertising purposes.

A further object is to provide aV slitting device of the type set forthincluding a replaceable cutting blade and novel holding and lockingmeans therefor.

Other and additional objects will become apparent to those skilled inthe art as the description proceeds with reference to the accompanyingdrawings, wherein:

FIG. 1 is a top plan view of a device embodying the present invention;

FlG. 2 is a side elevational view thereof;

FIG. 3 is a vertical sectional View taken along the line 3-3 of FIG. l;

FIG. 4 is an enlarged transverse sectional view taken along the line 4-4of FIG. 3;

FIG. 5 is an enlarged fragmentary sectional view taken along the line 55 of FIG. 3;

FlG. 6 is a perspective view of the blade and holder assembly; and

FlG. 7 is a plan view of the novel blade and illustrating the manner inwhich a plurality of blades are cut from a single strip of materialwithout waste.

Referring to the drawings, numeral 2 indicates the body portion of theslitting device of the present invention and as shown comprises asubstantially dat plate-like body having a front edge 4, a rear edge 6,and a bottom edge 8. The body is formed with a slot 10 extendingrearwardly from the front edge 4 and adjacent and substantially parallelto the bottom edge 8. That portion or the body between slot lil andbottom edge 8 is preferably pointed, as at 12, and is curved or somewhatrounded in transverse section as best seen in FIG. 5. A rectangularpassageway 14 is formed in the body 2 extending rearwardly from thebottom of slot 10, at 16, and in substantial alignment with slot 10. Thepassageway 14 extends rearwardly through the rear edge 6 of the body 2.which is formed with a transverse notch 18 into which the passageway 14extends. The passageway Y wardly from that position the passageway 14 isrelatively arrow and continues forwardly to define narrow grooves 2?.and 24 at the top and bottom of the slot 10. The grooves 22. and 24 areof a width to rather snugly but slidabiy receive the upper and loweredge portions of a cuttingblade 25. The cutting blade 26 is preferablyformed from a strip of suitable metal as indicated at 28 in FIG. 7 andis stamped therefrom with `a front edge 30 extending upwardly andrearwardly in an oblique direction from the bottom edge of the blade andthen curving upwardly and forwardly to form a hook portion near theupper edge of the blade.

The rear edge 32 of blade 26 is formed of complementary shape to theforward edge 30 so that the blades may be stamped from the strip 28without waste. In stamping the lades from a strip 2S, openings 34 areprovided near the upper edge of the blade at the rear end of the tang 36defined by the rear edge blade shape.

After stamping, the blades are sharpened at their forward edge to formthe cutting edge shown. Each blade 26 is securely fixed to a moldedholder 38 by having the tang 36 embedded and .intcrlocked with theholder 38. The material of holder 38 is molded around the tang 36 andextends through opening 3'4 and thus permanently and securely locas theblade and holder together as a unit.

'The holder .33 is of generally rectangular crosssectional shapecomplementary to the passageway 14 pre-` viously described and isprovided with an enlarged head 4i) at the rear end thereof which iscomplementary in shape to the notch 18. v Thus, the head 4l) serves as astop means to limit inward movement of the holder 38 in passageway 14 toa position where the cutting edge Sil of the blade 26 extends across thebottom portion of notch 10, as clearly shown in FIG. 2. It is understoodthat the upper and lower edges of the blade 26 at this. time reside inthe grooves 22 and 24 previously described.

The holder 33 is preferably molded of a synthetic resin material havingresilient characteristics and is molded to define a notch 42 at itslower edge. The holder further includes a rearwardly extending integralresilient linger 44 integrally joined to the holder 38 at the forwardend of notch 42. The linger 44, when unstressed, extends downwardly andrearwardly so that its rear end normally projects downwardly below thelower edge of holder 38.

The body 2 is provided with an opening 46 extending upwardly from itslower edge 8 into communication with the passageway 14 and is sopositioned that when the head 46 of holder 38 is rmly nested in thenotch 18 the free end of linger 4d projects downwardly into the opening46 and engages the rear edge thereof. Thus the finger 44 serves toreleasably lock the blade and holder in the body 2 against inadvertentwithdrawal while head 40 serves to prevent accidental forcing of theholder 38 too far inwardly in passageway 14. When it is desired toremove the holder 38 and blade 26 for purpose of replacement orotherwise, any slender instrument, such as indicated at 48, may beinserted in opening 46 to depress the end of resilient linger 44inwardly into notch l2 whereupon the head 45t may be grasped and theholder and blade withdrawn from the body 2. A new holder and blade areinserted in an obvious manner and pushed inwardly until the end offinger 44 snaps into opening 46 and the new blade and holder are thenlocked in position for use.

In the customary type of letter opener a sharpened blade is providedbearing much the same relationship to a slot as shown herein. However,it is customary for the cutting edge of the blade in such prior devicesto extend obliquely rearwardly and upwardly of the slot and to intersectthe upper edge of the slot at an acute angle. With such devicesconsiderable difficulty is encountered in having paper or whatever othermaterial is being cut jam and pile up in the angle between the cuttingedge and top edge of the slot. The shape of the cutting edge asdisclosed and described herein prevents such jamming since any paperfibers approaching the top of slot 10 engage the overhanging upperportion of the sharpened cutting edge 3! and are completely severed andcut without jamming against the top of the slot 10.

The manner of use of the disclosed device is obvious insofar as openingof letters, cartons or the like is com cerned, but it is to be pointedout, particularly with the shape of cutting edge shown, the device haswider utility. For example, it may be used to slit ish prior tocleaning. For this latter purpose it is preferred that the sharpenedportion l2 be made of metal, preferably non-corrosive. As shown in thedrawings, a metal tip 50 is formed and is provided with a tang 52 havingan enlarged head 53 thereon. The metal tip 50 is placed in the mold atthe time the body 2 is molded and the material of body 2 embraces andinterlocks with tang 52 and head 53 to securely lock the metal tip inplace.

While a single specic embodiment of the invention has been shown anddescribed herein, it is to be understood that the same is merelyillustrative, that other forms may be resorted to within the scope ofthe appended claims.

I claim:

1. In a slitting device, a tlat unitary body having front, rear, andbottom edges, a slot extending inwardly from said front edge adjacentand generally parallel to said bottom edge, a peripherally closedpassageway in said body extending from the rear of said slot, insubstantial alignment therewith, through said rear edge, a blade holderslidable in said passageway, a cutting blade xedly secured to said bladeholder and having a cutting edge extending obliquely across said slotand facing toward said front edge, and resilient locking means integralwith said blade holder and releasably engageable with stop means on saidbody for releasably locking said blade holder in said passageway.

2. A device as defined in claim 1 wherein said blade is formed so thatsaid cutting edge extends obliquely rearwardly from the edge of saidslot adjacent said bottom edge and then curves obliquely forwardlyadjacent the opposite edge of said slot.

3. A device as defined in claim 1 wherein said locking means includes anintegral resilient linger on said blade holder, extending generallyrearwardly thereon, and an opening extending from the outer surface ofsaid body into said passageway, the end of said finger engaging a sideof said opening.

4. A `device as defined in claim l wherein said body is provided with anotch extending across the rear edge thereof, said passageway openinginto said notch, said blade holder having an integral enlargement at therear end thereof complementary to and nested in said notch.

5. In a slitting device, a flat unitary body having front, rear, andbottom edges, a slot extending inwardly from said front edge adjacentand generally parallel to said bottom edge, a peripherally closedpassageway in said body extending from the rear of said slot, insubstantial alignment therewith, through said rear edge, a blade holderslidable in said passageway, a cutting blade secured to said bladeholder and having a cutting edge extending obliquely across said slotand facing toward said front edge, and resilient locking means securedto said blade holder and releasably engageable with an edge of anopening extending into said passageway for releasably locking said bladeholder against withdrawal from said passageway, said body being providedwith a notch extending across the rear edge thereof, said passagewayopening into said notch, said blade holder having an enlargement at therear end thereof positioned in said notch, and cooperating stop means onsaid enlargement, and said body, forwardly of said rear edge, forlimiting forward movement of said blade holder in said passageway.

References Cited in the file of this patent UNITED STATES PATENTS296,492 Wheeler Apr. 8, 1884 1,449,408 Hull Mar. 27, 1923 1,498,753Rendlich June 24, 1924 1,515,952 Joell Nov. 18, 1924 1,813,868 SmiraldoJuly 7, 1931 2,124,615 Foltz July 26, 1938 2,329,805 Wilson Sept. 2l,1943 2,535,555 Tilly Dec. 26, 1950 2,611,178 Whipple et al Sept. 23,1952 2,941,294 Vosbikian et al. June 21, 1960

